5.2 Detection and monitoring of pollution

Direct methods of monitoring pollution – Air pollution Measure the acidity of rain water to determine pH Measure CO 2, CO, or NO x levels in the atmosphere using a gas sensor Measure particulate matter suspended in the atmosphere

Direct methods of monitoring pollution – Soil pollution Test for nitrates and phosphates (Using LaMotte test kits)

Direct methods of monitoring pollution – Water pollution nitrate and phosphate tests fecal coliform tests tests for heavy metals (Hg, Pb, As)

BOD (Biochemical Oxygen Demand) – BOD is an indirect method that measures the amount of oxygen required to support respiration by organisms living in a water sample. high BOD indicates there are many organisms using oxygen for respiration low BOD indicates relatively few organisms needing oxygen for respiration high BOD = low DO levels = high pollutant levels, especially nitrate & phosphate low BOD = high DO levels = low pollutant levels

The Biotic Index Biotic Index – An indirect method that uses the presence or absence of key organisms to indicate the relative level of pollution in a stream. Advantage: Easy to use, especially for moderately or heavily polluted sites. Disadvantages: not specific enough, doesn’t fully account for habitat quality

Semi-Pollution Tolerant Pollution Tolerant Pollution Intolerant

Indicator Species Species that are present either only in polluted areas or only in unpolluted areas. – Lichens – Not present in air pollution – Rat-tailed maggot and sludge worms – Found only in polluted water – Gammarus - small crustaceans that are not found in high levels of salinity.